They look like something drawn by Dr Seuss, but saiga antelopes are a real thing. Unfortunately, we can't be sure if they will be a thing for much longer, because at the current rate they could be extinct within a few weeks, at least in the wild.

Saiga antelopes are not particularly rare for a large mammal, with well over 100,000 surviving. However, they have been classified as endangered since hunting slashed their numbers by at least three quarters in the 1990s, after the breakup of the Soviet Union weakened poaching controls. In the past few weeks an estimated 85,000 have died, and that figure, released on Friday, may already be out of date. Worse still, no one knows why.

In 2014, a study by the government of Kazakstahn reported just over a quarter of a million saiga in the country. A smaller number live in Russia and Mongolia, which so far have not been reported to have been affected in the same way.

Scenes like this could become a thing of the past. Credit: Dmytro Pylypenko via Shutterstock

A bacterial infection called pasteurellosis is considered to be the most likely cause, but experts in animal disease are flying in to investigate further. The Kazak ministry of agriculture says that large die-offs have happened before, but the loss of a third of a population in such a short time is almost unprecedented, not just for saiga, but for any long-lived species. It is unclear why a disease that was already widespread among saigas, and usually only killed those weakened by lack of food or other diseases, should turn lethal so quickly.

“It’s shaping up to be a complete catastrophe,” EJ Milner-Gulland, head of the Saiga Conservation Alliance told the Guardian. She added, “I’m afraid the animals are still dying and we are not actually getting a final number yet. I’m expecting that number to go up quite substantially in the coming days.”

The saiga have rebounded from population crashes before, having dropped as low as 21,000 after poaching peaked in 2003. Population crashes reduce genetic diversity, potentially making species more vulnerable to new diseases or mutated versions of old ones. On the other hand, the saiga's residence in regions prone to bitter winters and severe droughts has created a capacity to breed quickly when good times come along.